is the in car meter simply not accurate OR is the difference charging overhead and heat losses?

Perhaps both, but mostly charging overhead. Also, preheating/precooling adds to overhead but not kWh in the battery.

what is the relevance?

The goal is to determine how much electricity the LEAF takes to operate, and that is the number from the "wall".

my only concern is the kWh in the battery when I start the day and how many miles I get on that.

I don't really care about the extra kWh from the wall to run the charger and cooling system and heat loss during charging.

ie my concern is range not power from the socket.

In that case wall numbers are of no concern to you. But the EPA number referenced in this thread is a "wall" number, I believe, so comparing it to a dash meter reading isn't really relevant.

the car says I am averaging 4.9m/kW (and rising) in the 14 days I have had the car 1250 miles in that time.

is that number wrong?

Perhaps. The mileage efficiency meter has been reported to give erroneous results by some, but the numbers I get are consistent with what I would expect from my accurate wall measurements. YMMV.

Other sources of variability: the car's odometer might be a bit off and actual miles traveled versus reported by the odometer will vary somewhat depending on tire type, tire wear, and tire pressure. But the meter should give relative results that can be compared day-to-day and month-to-month.

One problem with the dash meter is that it is coarse: it only reports data to one figure past the decimal point. But that should be plenty good enough for a rough idea of overall mileage efficiency. One concern is that the number on the dash does not usually agree precisely with the mileage efficiency number on the nav console (you have one there too), at least on older LEAFs, such as your 2012 (it would be interesting to see if that has changed on newer LEAFs).

You can reset the meters. I reset my dash meter monthly and the nav console meter each day, just to get an idea of how I was doing that day. The monthly reset is to track seasonality: in the snowbelt mileage efficiency drops considerably in winter versus summer, as one might expect. Others like to leave one meter unchanged to get a sort of "lifetime" mileage efficiency number, although if the 12 V battery is ever disconnected that number will be lost.

Keeping an eye on the mileage efficiency meter, and resetting it periodically, can help in learning to drive the LEAF more efficiently, for those who care about such things.

is the in car meter simply not accurate OR is the difference charging overhead and heat losses?

what is the relevance? my only concern is the kWh in the battery when I start the day and how many miles I get on that.

I don't really care about the extra kWh from the wall to run the charger and cooling system and heat loss during charging.

ie my concern is range not power from the socket.

the car says I am averaging 4.9m/kW (and rising) in the 14 days I have had the car 1250 miles in that time.

is that number wrong?

when you plug your car in you should hear the faint noise of water pumps kicking in to cool the system. this is a standard overhead that varies little based on charging speed so this is why its good to have faster L2 charging than to use L1 charging. the rest is heat loss on the conversions where L1 wills this battle but the margin is not enough to offset the BMS overhead.

I am at 90% efficiency running at 4.8 KW. the other part as you suspected is the measuring is probably not the best in terms of accuracy either

I am beginning to wonder what the true capacity of the batteries are as they wear down. I think the system is fooled ornis straight up lying about capacity.

I average around 5m per kw. Yet the 8.9m trip to work at 35mph 40max takes a full 2kw as per leaf spy? (19.5kw to 17.5kw) (I really must be stupid. That is 4.5 miles per kw. I guess I am just more exhausted than I realized)

Once I get below 17kw things seems to stabilize and the gom actually becomes pretty damned accurate.

I am thinking my 19.5kw full charge is a fiction and the car rapidly settles down to its true capacity which would explain the rapid gom drop as it keeps recalculating from real time data

The problem I fear is that the capacity meter and by extension nissan is using this ficticious full charge reading instead of the true full charge which I suspect for me is 18.5kw

That would mean my capacity loss is down to 88% not the 90% leaf spy reports??

Not much difference now but could mean a pretty damned big difference at 55,000 miles

Thoughts?

Last edited by nerys on Tue Sep 30, 2014 11:40 am, edited 1 time in total.

As usual, I encourage all LEAF drivers to use actual range/recharge capacity data to find any errors in their cars reported (nominal) kWh use reports, and any errors in the LBC reports of battery capacity, rather than trying to force the data to support either their LEAF's kWh use or LBC battery capacity reports.

Part of that increase is from driver efficiency (I more frequently drive low-speed routes, and more often drive relatively slowly on them) and part is probably from an increase in vehicle efficiency, but I believe is nearly certain that there has been a significant change in the common data my LEAF reports as a "kWh" on the dash, Nav screen, and from CarWings.

Each of these "kWh", whether from the top or bottom of the pack, range tests as the same constant unit of energy. And each "kWh" seems to have ~constant Wh capacity from one charge to the next, in the short term.

The question I have tried to answer from range/recharge capacity tests on MY LEAF is whether each of these "kWh", as reported in common on the dash/Nav screen m/kWh and CarWings has actually had a constant Wh content over the last 3+ years (almost certainly not) or how much the Wh content per nominal kWh has increased (the subject of other threads).

In any case, since I finally took my LEAF down to turtle for a long-range test, I can now report that my LEAF still retained more than 100 mile maximum range (~6.1 m/kWh x ~17 kWh x ~1.023 CW/Dash m/kWh odometer error = ~106 miles) in my average driving conditions this Summer.

And I'm pretty happy about that.

7/13/14:

126.1 miles to turtle (5 gids ), 17.0 kWh...

All miles above are as reported by odometer...

KWH use is as reported by dash M/kWh, nav screen M/kWh and Carwings, trip (ERS) and daily.

My average is 4.0, all inclusive since new. On days I stick to town driving and I get 4.5

After two Phoenix summers I've lost two bars, and the battery is at 72% for a loss of 28%.

I've loved every minute of this car, but the range is too short, and the battery has lost and is losing far too much of it's potential for me to consider buying it off lease.

Even with the new "hot weather" battery, I'm not buying or leasing anther LEAF. It was a great experiment, but for our family's busy life with school, baseball, hockey, piano, many days I'm hitting a charger in the middle of my busy day. At first it seemed quaint but as the novelty of the electric car wore off and the battery lost capacity, it's become a burden.

dcxplant wrote:It was a great experiment, but for our family's busy life with school, baseball, hockey, piano, many days I'm hitting a charger in the middle of my busy day. At first it seemed quaint but as the novelty of the electric car wore off and the battery lost capacity, it's become a burden.

How much range do you think you'd need for an EV to not be a burden on your lifestyle? Or would more charging stations also work with a fresh battery? With all those stops, it seems that there could be enough time for opportunity charging to work if they were available.

If no matter what you do short of playing speed racer you got n 100 miles.

I think that will be the magic number.

One way they can do this is to softwarr restrict an oversized battery

So maybe you have 220m range. The system will only charge to 80% and only "tell you" it has 150 miles and it did charge to 100% ie lie to you.

This way as battery degrades or temps drop it can software "unlock" some of this range keeping the driving experience unchanged for the end user for much much longer.

That would go a huge way toward improving adoption and reducing average user anxiety and concerns.

I drive 40,000 miles a year minimum (6 weeks 3300 miles on my leaf

100 miles drop dead range would 100% eliminate any issues for me for 99.9% of my driving needs.

For the other .1% i would just use one of my gas cars. No big deal.

Right now the leaf works for me and i dont even have l2 charging yet (should be rectified today)

But it does require careful planning and a state of if its not driving it is charging. Always

The payoff is worth it though. after 20 years of drooling and pining i finally have an ev and it is costing me absolutely nothing over what i was paying before (even with insurance i am spending $100 less than i was spending on gasoline a month!)